1. Field of Invention
This invention is related to the data communication device, especially to the date communication device used for the data communication between an IC card and an IC Card read and write device.
2. Description of the Related Art
An antenna is formed on an IC card side when data communication is held between a non-contact type IC card and a read and write device of the IC card in the conventional designs. The antenna is configured from a conduction line loop and data communication is held by using induced electromotive force generated by applying an electric current to the loop. This type of data communication device is disclosed in Japanese Patent Application No. Hei 11-234164.
However, the application of an electric current to the conduction loop is required in the data communication device described above, which leads to a large consumption of electric power. The large consumption of the electric power is a serious problem especially for small scale devices which require low power consumption.
The shape of the antenna, which is made of the conduction loop, should be optimized depending on the frequency to obtain the maximum efficiency in the gain and radiation power. It leads to a problem of increased surface area of the antenna on the IC card as well as an increase of manufacturing cost.